Power briefly went off in the House of Lords on Monday evening (22 April) as a peer was mid-way through a speech.
Lights in the chamber flickered before going out while Lord Bellamy was speaking at the despatch box.
After television screens and microphones also turned off, the justice minister prompted laughter as he joked: "I must have said something controversial."
Lord Bellamy was able to continue reading his notes by using a table lamp during a short debate on support for parents considering separation.
It came amid the late-night back-and-forth between the Commons and Lords over amendments to Rishi Sunak's controversial Rwanda bill.
